1. Field of the Invention
This invention relates to back exercise machinery, and more particularly to a device that tilts the user backwards so that the spine may be exercised and stretched while it is not compressed.
2. Description of the Related Art including information disclosed under 37 C.F.R. SS 1.97-1.99.
The human spine allows people to walk in an upright manner and is adapted to undergo many stresses. However, with these stresses, the spine is also subject to a number of injuries, disabilities, and diseases that cause many people severe discomfort and pain.
The act of walking upright exerts a significant amount of stress upon the spine as the spine supports the entire upper torso. Through years of use, the accumulation of injuries, and the onset of increasing age, the spine can become less limber and more prone to injury and disease. Pinched nerves and diseased discs are two of but several painful conditions that originate from the spine.
One reason the spine becomes a focal point of injury and disease is that for most of the waking hours, the spine is continually subject to compressive and downward forces. As the base of the spine is held fixed by the pelvic girdle, the upper portion of the body pushes downward upon the spine to compress the several vertebrate together. As this downward, compressive force upon the spine is continually exerted upon it day after day, small injuries and/or insults can be inflicted upon the spine. Further, such small injuries or insults can be exacerbated by the ongoing daily stresses upon the spine. As only a healthy spine can move and articulate properly, any injury or insult to the spine can inhibit normal movement and can even make bedridden an otherwise healthy person.
One way to avoid injury to the spine is to strengthen it by exercise. Exercise works to strengthen other parts of the body, and to help them to withstand injuries. The same is true of the spine. With proper exercise, the spine can become a stronger member of a healthy body and can improve a person's posture and overall well-being. While exercise improves the spine, typical exercises only work the spine in its usual, compressed state. The spine would be made stronger and more healthy by exercising it while it was in a decompressed state and would greatly complement spinal exercises that work on the spine while in its normal compressed state.
In order to better exercise the spine when it is decompressed, devices have been developed that turn a person upside-down so that the spine can be stretched and flexed while the spine is not subject to its downward compressive forces.
One such device is in the form of a pair of boots that attach to the person's feet in a snug and secure manner. Attached to the boots are a pair of large hooks that serve to support the person by engaging a sturdy bar. The bar is fixed in position at a height somewhat above the height of the person. The person grabs the bar, swings the boots up to the bar, and engages the boot hooks on the bar. The person then releases the bar with his hands, but stays attached to the bar with his feet. Gravity then exerts a downward pull on the now free-swinging body of the user so that previously compressed skeletal structures are allowed to stretch out.
In this position, the user can flex and stretch the spine with its accompanying ligaments and tendons. As the upper portion of the body now pulls downward on the spine, the compressive forces previously exerted upon the spine are removed, allowing the intervertebral discs some room to maneuver and to re-seat themselves between the vertebrae. Other spinal structures may also re-align themselves. When the person is through exercising, the person grasps the bar and disengages the boot hooks from the bar to lower the feet to the ground.
Several problems arise from the use of such "gravity boots". Once the user has disengaged the bar with his hands and swings free, blood from the lower extremities flows towards the head as the head is now the lowest part of the body. The upside-down position attained by the body also changes the pressure exerted by the blood on the body, including the head. It is possible for the shift in blood flow to exert such pressures upon the head and brain that blood vessels inside the head may burst, possibly causing a stroke.
It may also be difficult for someone using gravity boots to disengage the boots from the bar. Having attained an upside-down position, the user must reach back up to the bar by raising the hands and torso up to the bar. If due to physical weakness or immobility the user cannot reach the bar, he or she will not be able to disengage the boots from the bar. Unless the user is aided by another, he or she will be left hanging indefinitely.
Another device that has been developed to relieve spinal pressure for exercise uses a rotating bar or wheel that allows the user to engage the apparatus from an upright position and then to turn himself upside-down by rotating around a central hub located at a height approximately at the user's midsection.
Such a device allows the user to disengage himself by rotating the device from an upside-down position to a right side-up position, avoiding the problem of indefinite hanging present with the gravity boot device. However, the problems associated with blood flow and pressure upon the brain remain and can have the same catastrophic consequences as with the gravity boots.
For both of these devices, the user decompresses the spine by hanging upside-down. However, hanging upside-down does not decompress the entire spine as the curve of the lower back is maintained. When a person hangs upside-down, the curve of the lower spine is only removed when the person pulls his knees slightly toward his chest, an act that is only achieved with great difficulty while freely hanging upside-down. As the curve of the spine at the lower back is maintained by gravity boots and the rotating apparatus, a person cannot entirely decompress the spine. Any stretching or exercise performed by the user by necessity does not stretch or exercise an entirely decompressed spine.
While for those of more robust constitutions, the act of turning oneself upside-down presents no problems, and may even be a pleasant change in an exercise regimen, those of weaker constitutions or more frail dispositions may require exercise or the ability to stretch in a position that relieves the downward and compressive stress normally imposed upon the spine. Using the devices mentioned above, people with more delicate health conditions are subject to some, even catastrophic, risk.
It can be seen that those who would exercise their spine in a stretched condition have a need for a device that allows decompression of the spine without exerting undue pressure upon the user. A further need is also present in that such a device should be easily engaged and disengaged by the user. Such a device should also remove at least somewhat the curvature present in the spine so that the entire spine can be stretched and flexed.